Sanding machine



15, l"935 A. G. MCCALE'B 2,064,483

SANDING MACHINE l Dec. 15, 19,36. A, G MCCALEB 2,064,483

` SANDING MACHINE Filed Oct. 18, 1955 2 Sheets-Sheet 2 Patented Dee. 15,193ev PATENT OFFICEk vsriNmNo. MACHINE Albert G. McCaleb, Evanston,Ill., assigner` to Duro Metal Products Company, Chicago, Ill., acorporation of Illinois Application October. 18, 1935, Serial No. 45,563

3 Claims.

, My invention relates to sanding machines and is particularly concernedwith improvements in sanding machines of the type characterized by anabrading element in the form of a power driven l belt. The principalobject of the invention is to provide a sanding machine of theaforementioned type in which the belt runs on a roller that has adequatebearings at both ends, although no part of the machine lies laterallyoutside of one of the edges of the belt tocontact with asurface at rightangles to the surface upon which the lower run of the belt is operating.

No sanding machine ofthe. prior art, to my know1edge,fpresents all ofthe'foregoing features 16 in combination, although all l are desiderata.

Patent4 to Emmons No. 1,821,624, for example,

discloses a sander which exhibits all of the aforef said desiderata,except the provision of bearings at both ends of the belt rollers.vPatent to Gustafson et al. No. 949,181, disclosesy a machine which alsoexhibits some of said desiderata.

Both Emmons and Gustafson yet al., however,

found it necessary to employ rollers, each supportedonly at one of itsends, in' order to keep any part ofthe machine from projecting laterallybeyond that edge of the belt which is intendedto lie and movekimmediatelyadjacent to a surface normal to the one on which the belt isoperating. k l v The present invention, in one of its aspects, may besaid to consist in the provision of a sanding machine comprising arollerv driven belt, on the lower run'of which the-weight of the machineis carried, in which all parts of the machine frame and. the bearingsfor the rollers lie wholly to one side of one of' the edges of the beltnotwithstanding that each roller is providedwith adequate bearings atboth ends thereof, in contradistincrtion to those vsanding machines ofthe prior art wherein the problem of locating all parts of the machineframe andbearings on one side of one of the edges of the belthasbeenpartially compromised, byl the dubiousand undesirable expedient ofdeprivingeach roller of support at one of g5-.its ends.

beyond which no othery part of the sanding machine should project.`

While I have chosen to illustrate the improvements of the presentinvention as incorporated 55 in` a sanding machine of the type that isdriven Y -A salientfeature ofthe present invention is the from aseparate motor through the agency of a flexible shaft, I wish to have itunderstood that the improvements of the present invention are equallyapplicable to machines that are wholly self-contained in the sense thatthey carry their own motors. Other features, objects and advantages ofthe invention are apparent from the following detailed description,wherein reference is made to the accompanying two sheets of drawings,showing a preferred form of sanding machine.

Fig. 1 of the drawings is a perspective view of the sanding machineshowing a driving motor and flexible shaft connected therewith;

Fig. 2 is a side elevational view thereof;

Fig. 3 is a Vhorizontal sectional view, taken on the line 3--3 of Fig.2;

Fig. 4 is a vertical sectional view, on an enlarged scale, taken ontheline 4 4 of Fig. 2;

Fig. 5 is a vertical sectional View on a similar scale, taken on theline 5--5 of Fig. 2;

Fig. 6 is a fragmentary horizontal sectional view, taken on the line 6 6of Fig. 2, and` Fig. `7 is an elevational view of the bearing bracketfor the adjustable roller.

These specific drawings and the specific description that follows merelydisclose an illustrative embodiment of the invention and are not toimpose limitations upon the claims.

All the metal parts of the sanding machine, with the exception of thebolts, screws, shafts and bearings, are preferably cast vfrom analuminum alloy so that the device may be cheaply constructed,l and oflight weight. The frame II of the machine may be open at the front andthe bottom and at one side, with a closed top I2 and side I3. At therear of the frame or housing II maybe provided 'an enlarged portionhaving a flat top I4 and closed rear end I5 to which are attached thelegs I6 and I1 of the handle I8 of the machine. The rear end of theframe is conveniently concaved to accommodate the operators hand as itgrasps the handle, and a second 'lll handle I9y shaped like a door knobVmay be screwed to the top member I2 of the frame for the other hand ofthe operator.

Means may be provided at the front of the side member I3 ofthe frame forsupporting one end of aroller. Thus, the side member I3 may vhave aboss20 with a bore in which is fixed a bearing 2I of `any suitablebearing metal. In this bearing is journaled the end 22 of a shaft havinga knurled portion 23 to receive a roller 24 with a drive fit. 'Ihe framealso carries means for rotatably mounting the other end of the roller,having a support for the part of a sanding belt running on the rollerthat extends past the end ofthe roller. In the device illustrated, theshaft upon which the roller is mounted has its other end 2l journaled ina bearing 26 xed in a bore in an arcuate shoe 21, which is formed at theend of a web 28 integral with the side member I3. A shoe is preferableto a roller for supporting the overlapping part of the belt. because ashoe can be made to extend close to the outer edge of the main roller,

while a roller used in place of a shoe would have to be spaced from themain roller to provide room for a support between the two rollers tocarry their bearings.

lThe other roller of the machine is preferably supported by a bracketthat is adjustable relatively to the frame. For mounting the adjustablebracket, there may be inserted in a pair of bores, in the shoulder 23 atthe front of the 'enlarged rear portion of the frame, two bolts 30 thathave headless ends fixed by means of set screws 3i in bores in the upperarm 32 of the adjustable bracket. In order that the bracket may befreely adjustable, the bores in the shoulder 29 are made slightly largerthan the bolts, and a tapped hole is provided between the bores toreceive a screw bolt 33 whose end bears .against the upper arm 32 of theadjustable bracket. To adjust the tension of a belt running on the tworollers by moving the bracket forward or backward the nuts on the bolts30 are screwed up. or the screw bolt 33 is screwed in. The bracket canalso be tilted slightly to cause the axis of its supported roller totilt ina horizontal plane, 'by screwing up the nut on one bolt more thanon the other. In this manner the belt can be maderto run to one side orthe other. l

Depending from the upper arm 32 of the adjustable bracket may be a leg34 at the end of which is formed a boss 35 having a bore containing abearing y36 of any suitable bearing metal. This bearing receives the end31 of a shaft having a knurled portion 33 for the securing of a roller39 similar to the roller 24. The roller 39 is preferably provided with asupport for its other end' that is similar to the support for thecorresponding end of the roller 24, except that it is integral with theadjustable bracket rather than with the frame. To support this end ofthe roller the shaft may have its end 40 journaled in a bearing 4| xedin a bore in an arcuate shoe 42 formed on the end of an arm 43 thatextends around the roller from the depending leg 34 of the bracket. Theroller may be driven by a flexible shaft 44 threaded into the end 31 ofthe'roller shaft, the threads running in the direction in which theshaft is to be rotated. The flexible shaft 44 is provided with a cover'45 and is driven by a motor 46.

Also included in the device may bea means for supporting the frame uponthe lower run of the belt that passes over the rollers, such as a shoe41 extending nearly the whole distance between the rollers. Supportingthe sanding machine upon the shoe is conveniently carried out byprovision of a hollow boss 43 onthe top of the shoe, into which isdriven a heavy pin 43 that is fixed by means of a set screw I! in an earIl extending inward from the side member I3. To retard conduction ofheat generated by the friction of the belt against the work, the shoe 41is covered -with one or more loyers 52 of heat-insulating material, suchas cork. These layers may in turn be covered with a friction reducingapron 53 of sheet steel having a flangev I4, which is screwed to theshoe to hold the apron 33 in place, and which is separated from theapron by means of a flexible crease that permits the apron to adjustitself to the work. Around the shoe and the rollers is wrapped a belt 56of flexible abrasive material such as emery cloth or sand paper. Theshoe is adjusted to cause the belt to project downward to a slightextent between the rollers so that a fiat work engaging surface ispresented. In order that all parts of the machine may lie wholly insidethe plane of the edge of the belt, the shoe and rollers should extend nofarther outward than the belt edge. The frame preferably does not evenextend as far out as the belt (see Figure 4). The rollers 24 ond 39 mayhave a slight crown opposite the middle of the belt to keep the beltfrom running olf to one side and may be covered with resilient rubbertubes 58 that grip the roller surfaces and provide antislip engagementwith the interior of the belt.

The rsanding machine that has been described may be modified, andvarious other devices em- --bodying the substance of the invention maybe constructed, to meet various requirements.

Having thus described my invention, I claim: l. In a sanding machineI incombination, a

frame, a drive roller and an idle roller, eachhaving one `end rotatablysupported by the frame, a

sanding belt on the rollers extending past their other ends, means forsupporting the frame upon the lower run of the belt, and an arcuate shoecarried by the frame for supporting the part of the belt that overlapseach roller having means for rotatably supporting the other end of theroller and lying inside the plane of the edge of the belt.

' 2. In a sanding machine, in combination, a frame, a drive roller andan idle roller, each having one end rotatably supported by the frame, asanding belt on the rollers extending past their other ends, means forsupporting the frame upon the lower run of the belt, and an arcuate shoecarried by the framefor supporting the part of the belt that overlapseach roller having means for rotatably supporting the other end of theroller and lying inside the plane of the edge of the belt, the arcuateshoe carrying the drive roller being adjustably mounted on the frame fortensioning the sanding belt on the rollers.

3. In a sanding machine, in combination, a frame. a. drive roller and anidle roller, each of said rollers having both of its ends supported bythe frame, an endless sanding belt on the rollers, said belt,overlapping corresponding ends of the rollers and extending to a plane,at right angles to the roller axes, beyond which no frame part extends,and auxiliary belt-supporting members at those ends of the rollers whichare overlapped by the belt, each said auxiliary belt-supporting memberbeing carried by a frame part which lies between those portions of thebelt which extend between the rollers, and each said auxiliarybeltsupporting member presenting a curved surface, concentric with theadjacent roller, for engaging and supporting the belt edge which over-.ALBERTV G. MCCALEB.

